rename PKG_CONFIG_LIBS_PRIV to PKGCONFIG_LIBS_PRIV

i.e.: do not steal PKG_CONFIG namespace.

CMakeLists.txt

@@ -2267,12 +2267,12 @@ if(NOT WINDOWS OR CYGWIN)
     set(ENABLE_STATIC_FALSE "")
   endif()
   if(SDL_SHARED)
-    set(PKG_CONFIG_LIBS_PRIV "
+    set(PKGCONFIG_LIBS_PRIV "
 Libs.private:")
     set(ENABLE_SHARED_TRUE "")
     set(ENABLE_SHARED_FALSE "#")
   else()
-    set(PKG_CONFIG_LIBS_PRIV "")
+    set(PKGCONFIG_LIBS_PRIV "")
     set(ENABLE_SHARED_TRUE "#")
     set(ENABLE_SHARED_FALSE "")
   endif()

configure

@@ -648,7 +648,7 @@ ENABLE_STATIC_FALSE
 ENABLE_STATIC_TRUE
 ENABLE_SHARED_FALSE
 ENABLE_SHARED_TRUE
-PKG_CONFIG_LIBS_PRIV
+PKGCONFIG_LIBS_PRIV
 SDL_RLD_FLAGS
 SDL_STATIC_LIBS
 SDL_LIBS
@@ -26022,12 +26022,12 @@ SDL_STATIC_LIBS="$EXTRA_LDFLAGS"
 
 
 if test x$enable_shared = xyes; then
-    PKG_CONFIG_LIBS_PRIV="
+    PKGCONFIG_LIBS_PRIV="
 Libs.private:"
     ENABLE_SHARED_TRUE=
     ENABLE_SHARED_FALSE="#"
 else
-    PKG_CONFIG_LIBS_PRIV=
+    PKGCONFIG_LIBS_PRIV=
     ENABLE_SHARED_TRUE="#"
     ENABLE_SHARED_FALSE=
 fi

configure.ac

@@ -1,8 +1,9 @@
 dnl Process this file with autoconf to produce a configure script.
+AC_PREREQ([2.59])
 AC_INIT
 AC_CONFIG_SRCDIR([src/SDL.c])
-AC_CONFIG_HEADERS(include/SDL_config.h)
-AC_CONFIG_AUX_DIR(build-scripts)
+AC_CONFIG_HEADERS([include/SDL_config.h])
+AC_CONFIG_AUX_DIR([build-scripts])
 AC_CONFIG_MACRO_DIR([acinclude])
 
 dnl Save the CFLAGS to see whether they were passed in or generated
@@ -4416,12 +4417,12 @@ AC_SUBST(SDL_LIBS)
 AC_SUBST(SDL_STATIC_LIBS)
 AC_SUBST(SDL_RLD_FLAGS)
 if test x$enable_shared = xyes; then
-    PKG_CONFIG_LIBS_PRIV="
+    PKGCONFIG_LIBS_PRIV="
 Libs.private:"
     ENABLE_SHARED_TRUE=
     ENABLE_SHARED_FALSE="#"
 else
-    PKG_CONFIG_LIBS_PRIV=
+    PKGCONFIG_LIBS_PRIV=
     ENABLE_SHARED_TRUE="#"
     ENABLE_SHARED_FALSE=
 fi
@@ -4432,7 +4433,7 @@ else
     ENABLE_STATIC_TRUE="#"
     ENABLE_STATIC_FALSE=
 fi
-AC_SUBST(PKG_CONFIG_LIBS_PRIV)
+AC_SUBST(PKGCONFIG_LIBS_PRIV)
 AC_SUBST(ENABLE_SHARED_TRUE)
 AC_SUBST(ENABLE_SHARED_FALSE)
 AC_SUBST(ENABLE_STATIC_TRUE)

sdl2.pc.in

@@ -10,5 +10,5 @@ Description: Simple DirectMedia Layer is a cross-platform multimedia library des
 Version: @SDL_VERSION@
 Requires:
 Conflicts:
-Libs: -L${libdir} @SDL_RLD_FLAGS@ @SDL_LIBS@ @PKG_CONFIG_LIBS_PRIV@ @SDL_STATIC_LIBS@
+Libs: -L${libdir} @SDL_RLD_FLAGS@ @SDL_LIBS@ @PKGCONFIG_LIBS_PRIV@ @SDL_STATIC_LIBS@
 Cflags: -I${includedir}/SDL2 @SDL_CFLAGS@